Air compressor



Aug. 6, 1940. 5 PYTLEWSK] 2.210,431

AIR COMPRESSOR Filed July 27, 1938 4 Sheets-Sheet l if n.

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Aug. 6, 1940. .s. PYTLEWSKI AIR COMPRESSOR Filed July 27, 1938 4 Sheets-Sheet 2 6 W E W 7w j wu W X 9 Wm fmnmw Z 0! Wm 77 I I f Aug. 6, 1940- s. PYTLEWSKI AIR COMPRESSOR 4 Sheets- Sheet 3 Filed July 27, 1938 m we k Aug. 6, 9 s. PYTLEWSKI 7 2,210,431

' AIR COMPRESSOR Filed July 27, 1958 4 Sheets-Sheet 4 Q 4; iii.

Patented Aug. 6, 1940 N STATES PATENT, OFFICE ,v

16 Claims.

An object and feature of my inventionv in an air compressor is in eifect a multiple stage compressor in which the air is first partially compressed and then by a second action is sub- 5 jected to further compression and preferably the compressions are effected by a reciprocating pump type of mechanism. A further object and feature of my invention is in the secondary or main compression to compress the air by a long stroke of a pressure piston operating in a cylinder, such stroke being very long in comparison with the diameter of the cylinder and piston. A,

further object and characteristic of my inven tion is preferably to employ a single initial compressor and two or more long stroke reciprocating compressors which operate alternately, that is, while one compression cylinder is on the compression stroke, the other is on the recession or being filled with the initial compressed air from the initial stage compressor. A further characteristic of this long stroke and alternate compression of air is that it allows a time period for the dissemination of heat due to compression and therefore by my equipment the air is compressed and pumped for instance to a storage tank without undue increase of temperature due to the action of compression.

Considered in more detail a further object and characteristic of my invention is in the employrnent of two or more long compression cylinders, each with its piston, these being very long in comparison with their diameter and in which each piston rod is provided with a rack. 'A power drive provides a pinion engaging with each rack and each pinion is controlled by an individual clutch, there being a continuous drive to both or all of the clutches, however, by an interacting mechanism, while one clutch is closed or driving a rack and piston downwardly on the power stroke, the other of two clutches is open permitting upward movement of the rack operated by the second pinion and hencethe upcausing the initially compressed air to elevate I the piston, piston rod and rack in one cylinder when the clutch operating in conjunction with such rack is open. This raises the piston to 55 thetop of its stroke and develops an initial compression of'air in one of the'cylinders. At the same time'theflow of air to the second cylinder iscut oiT and this is on its power stroke with the rackbeing positively forced downwardly by a close'd clutch connection to the driving mech- 5 anism. Inasmuch as the power stroke by the positive drive is faster or of a less time period than the recession or filling stroke under the 'action of the initially compressed air, the control mechanism is such that immediately after'lo a compression stroke when one clutch is opened which has caused this power stroke, there is a slight upward bounce of the piston due to the release of the pressure of the air confined in the lower part of the piston and between the '15 pistonand the adjacent check valves. Such piston may then rest until the second piston hasreached the top of its stroke 'on' the recession and the filling of the second cylinder, then as soon as the second cylinder starts down- 20 wardly on its compression stroke, the first cylinder receives its air charge and the piston of the'first cylinder rises, the clutch connection to the first cylinder being open. I

My invention is illustrated in connection with 25 the accompanying drawings, in which:

Fig. 1 is a front elevation of my invention, certain parts being broken away to illustrate internal construction.

Fig. 2 is an elevation taken in the direction of 30 the arrow 2 of Fig. 1 showing part of the machine only toillustrate the crank operation of the initial air compressor pump. I

Fig. 3 is an enlarged front elevation of the reversing air valve mechanism as depicted in 5 Fig. 1. i

'Fig. 4 is an elevation taken in the direction of the arrow 4 of Fig. l of the toggle levers and spring equipment for producing a quick action of the switch control rods. 40

Fig. 5 is a section on the line 55 of Fig. 4 in the direction of the arrows.

Fig. 6 is a vertical section through the mercury switch housing box taken on the section line-$c of Fig. 1 in the direction of the arrows, the mercury switch being shown in elevation.

Fig. '7 is a vertical section on the line l1 of Fig- 1' through one of the compressors showing the piston inits lowermost position, the cylinder and'piston rod being broken to shorten the illustration.

Fig. 8 is a vertical section on the line 8-8 of Fig; 7 in the directionof the arrows to'illustrate the construction of the resilient piston.

Fig'. 9 is a vertical section" throu h the base of one of the long compressor cylinders illustrating the inlet or charging valve and the outlet or discharging valve.

Fig. 10 is a horizontal section on the line Ill-40 of Fig. 9 through one of the valve ports.

Fig. 11 is a diagram in elevation to illustrate the mechanical control of air valves and the electrical control of magnetic clutches, the supporting and driving structures being omitted for sake of. clarity of illustration.

Fig. 12 is a partial horizontal section on the line |2-|2 of Fig. 1 in the direction of the arrows.

Referring first to the general construction of the diagram of Fig. 11, the initial or supply air pump is designated by the numeral N. This as hereunder described is a reciprocating type of compressor in which air is discharged at both ends of the stroke, therefore there is a lower discharge pipe 2 and an upper discharge pipe l3.- -1'I hese connect to 'a common pipe M from which pipes l5 and I6 supply alternately operatedvalves and I8. These valves have discharge pipes |9 and 20 connecting respectively to the inlet of the main compression cylinders 2| and 22. The compressed air discharge from such cylinders is by the discharge pipes 23 and 24 in which there are check valves 25 and 26. These pipes'connect to a common pipe 21, this having a check valve 28 therein which leads to the storage tank 29 in which the air is maintained under pressure. The compression cylinders each have a piston indicated at 35 and 36 with piston rods provided with rack bars 31 and 38. Each rack meshes with a pinion 39 and i4!) driven through; the medium of magnetic clutch assemblies 4| and 42. In Fig. 11 the particular drive to the clutches is not shown. The control for the clutches designated by the assembly numeral 5|] employs magnetic switches 5| and 52 actuated each by a quick shift type of rod 53 and 54. Each rod has an upper bent end 55 and'a lower bent end 58 for a purpose hereunder described.

Attached to the racks 3'! and 38 there are cross heads El and 58 which engage the inturned ends of the rods 53 and 54 giving these a slight up and down movement, the snap action being given by a toggle lever spring assembly hereunder described. These rods 53 and 54 therefore shift the mercury switches 5| and 52 alternately ener gizing the magnetic clutches. Thus when a piston and its connected rack is in an uppermost position, the tilting of the switch causes an energi-zing of the magnetic clutch associated therewith and a closing of such clutch. The drive through the pinions 39 and 48 to the respective racks 31 and 38 gives a downward movement to the pistons 35 and 36 in the proper alternative order. When the piston reaches the bottom of its stroke, the rods 53 and 54 are tripped downwardly, thus causing a reversal of a mercury switch and (lo-energizing of the magnet associated with the particular piston at the bottom of its stroke, thereby opening the clutch, permitting the pinionto ride idly on the rack.

The operation of the reverse acting valves l1 and l8 is by means of actuating rods 8| and 82, each of which has an angle end 63 .and attaches toa-cross head 51 or 58. The pawls 63 and 64 on the lower end of the rod 6| and 62 respectively operate the reversing lever 10 which actuates the reversing valves l1 and I8 as hereunder described in detail.

The above described equipment is mounted on the base substantially as shown in Figs. 1 and 12 in which a substantial frame 10 has a base supported on legs 12. There are standards or posts I3, 14, 15 with cross members 16 and a top beam 18. The cylinders 35 and 36 are suitably mounted A column 88 extends upwardly from the top beam 18 and has a cap plate 8| mounted thereon. A pair of fixed guide rods 82 and 83 connect between the beam 18 and the plate 8|. The rack bars 31 and 38 which form a continuation of the piston rods have a back thrust support 85 (note Fig. 7) which employs a bracket 88 on the beam 18 and a thrust roller 81. The pinions 39 and 40 each have a pinion shaft 88 mounted in suitable journal supports, each of these being in alignment with the respective magnetic or similar clutches 4| and 42. The drive to these clutches is by means of gears 89 mounted on a clutch shaft suitably mounted in a journal 98. Each gear 89 is driven by a pinion 9 I, note Figs. 1 and 2. A transverse shaft 92 connects both of the pinions 9|, one of which is driven by a pinion 93 on a drive shaft 94, such shaft being suitably journaled in the frame, the shaft 94 being illustrated as driven by a belt and pulley drive 95 actuated by an electric motor 96. A fly wheel 97 is driven by means of a latch gear 98 on the shaft 94 meshing with the pinion 99 on the fly wheel shaft Hill which is suitably journaled in the frame. By this construction and through the regulation by the fly wheel, the drive is carried to the opposite gears 89 by the through shaft 92 and hence there is a constant drive to the clutch shafts but of course the clutches are controlled alternately as above described so that when one clutch is closed the other is open.

The control of the switch for the magnetic clutches is as above described in which the cross heads 51 and 58 are each guided by being provided with a perforation ||l| through which the guide rod 82 extends. A compression spring M2 on the rod operates as a buffer spring against the cross head and the plate 8| when such cross head is in its uppermost position. The cross head as above described, engages the end projections 55 and 55 of the quick shift rods 53 and 54 to operate the mercury switches 5| and 52.

For instance, describing the action relative to the rod 53, a toggle spring assembly designated H8, note Figs. 4 and 5, employs a cross bar connectedto the rod 53, this having a pair of slots. H2 in the opposite ends. A pair of links H3, H4 are pivoted at M5 to the column 88. These links also have a loose or sliding pin connection H6 to the slots H2. A toggle spring connects between hubs l8 on the pin connections 5. This is more or less of a conventional toggle spring arrangement. As soon as the links 3 in the movement of the rod 53 pass by the dead center of the pivot I I5, the spring causes an immediate quick action either upwardly or downwardly of the rod. Such rods 53 and 54 are guided in lower and upper guide brackets I20 and |2| mounted on the column 80, note Fig. 1. The mercury switch for instance describing 5|, is substantially as shown in Fig. 6'. A housing I25 is mounted on the column 88 and has one end of the switch container I26 pivoted thereto. The rod 53 has aslotted bracket I21 which is engaged by a pin I28 on an extension arm I29 of the switch tube. Therefore in the steep upward and downward action of the rods 53 and 54, the mercury switches are reversed. These switches are illustrated as having each a pair of electric leads I35 with connection through brushes I 3|" to the rotating conductor disks I32 mounted on the constant drive shaft. From the gears 89 leads I33 extend to a source of power. By this arrangement when the cross heads 51 or 58 approach the upper or lower ends of their stroke, they respectively contact the ends 55 and 56 of the rods 53 and 5s and give these sufficient movement to operate the toggle springassembly of Figs. 4 and 5 a movement through the dead center and then a quick movement of the switches. This causes an energizing of one magnetic clutch,

.either 55 or 62, while the other is deenergized.

The magnetic clutches are of a standard type and shift to the closed clutch position when electrically energized.

The air flow and the initial air compression in the supply pump H is as follows: this pump is illustrated as a cylinder and reciprocating piston type, note Figs. 1 and 2, having a suitable mounting in the frame and with a piston rod I operating the piston, a pitman I36 and a crank H1. The crank is connected to the pinion 9| and has sufficient throw to develop the full stroke of the piston. This is a double acting pump of a standard type and as above mentioned, discharges through the pipes I2, I3 and the common pipe It to the control valves I1 and I8.

These valves are of a standard type connecting in the pipes I5, I6 and I9, 20. In order to operate these valves in an alternate manner, each valve is provided with a rotatable valve stem I40 and MI to whichare connected disks I42 and I43 having intermeshing segmental gears I44. An operating lever arm I45 is illustrated asconnected to the stem IIiIL- This rod is of equal length from the stem I60 to the tooth M6 and to the tooth I41 at its opposite end. These are actuated respectively by the pawls 63 and 64. Each pawl is provided with a bell crank I48 with a thrust arm I49 and a lever arm I50, the lever arm being connected by a spring I5I to a rod-such as 61 or 62. By this construction the pawls only are operative on their downward motion, causing an angular shift in such a manner to operate the valves I1 and I8 in a reverse manner, that is, when one valve is open, the other is closed and thus there is a supply of the air either to the cylinder 2! or 22.

The particular construction of the pistons 35 and 36 is shown in Figs. '1 and 8 in which there is a piston head I which has a cylindrical wall !56 and a closed head end I51. This is provided with piston rings i513 engaging the cylinder. A cap ring I59 is secured to the top of the wall I56. A movable piston head I60 is normally thrust upwardly by a compression spring I6I engaging between the base head I51 and the movable head I60. The piston rod has a neck I62 with a securing device I63 making a firm attachment of the piston rod and hence the racks to'the movable head 560. It will thus be seen that when the piston reaches the bottom of its stroke and contacts the bottom of the cylinder, the spring I6I compresses, allowing a slight further downward movement of the piston rod and rack and the movable head I60. This is to take care of any coasting of the clutch and its pinion subsequent to the opening of a clutch. The clutches are closed for driving the racks and hence the pistons downwardly and are open for the upward movement, the pistons and racks being elevated by the inflow of air as hereunder described.

Check valve assemblies, designated I10, note Figs. 9 andlO, are provided in the base- I1I of eachzof the cylinders Z'I an d 22. These are constructed in a similar manner but reversed, therefore only one will be described in detail. There is a recess with a valve seat I12 in the base "I, a plurality of ports I13 leading to a bore I14, such bore either being connected to a supply pipe or leading to the interior of the cylinder. The valve plug I15 has a conical bearing with the seat. It is provided with a stem I16 and a coil spring I11 tends to hold the plug in the closed valve position, such plug being raised from its seat by the action of the air under compression.

The action of the device is substantially as follows: as above mentioned, air is continuously pumped by theinitial pump I I and the discharge leads to'the valves I1 and I8. Presuming that one of the pistons either 35 or 36 of the long cylinders 2| and 22 has been forced downwardly on a compression stroke through the action of the pinion operating on its associated rack, this drives the air out one of the long cylinders, this being forced through the pipe 21 to the storage tank 29. This tank is provided with a pressure gauge I86.

On account of a small amount of air being trapped in the bottom of the cylinder, when the clutch is open releasing the rack from its drive, the piston which has reached the bottom of its stroke has a slight upward rebound. At this instant of openingone clutch the other clutch is closed to obtain a down drive of the piston in the other cylinder, the Valves I1 and I8 have been reversed so that the piston now at the bottom of its stroke is elevated by the air under pressure forced in from the first pump II. This causes a somewhat slow lift of the piston which is somewhat slower than the downward movement of the pistons when positively driven by the pinion and racks. Therefore as soon as one clutch has been opened with its associated piston at the bottom of its stroke, it is not necessary that this immediately starts the upward movement as the other cylinder must have its piston completely at the top of its stroke before the valves are reversed and the magnetic switches reversed to change the drive. It is to be noted that the switches for the clutches are operated when the pistons are approximately at the top of their stroke and that each clutch is actuated independent of the other. Therefore one piston may bedescending while the other is standingat rest or on its slow upward movement actuated by the air from the first pump II.

. Various changes may be made in the details of the construction without departing from the spirit or scope of the invention as defined by the appended claims.

I claim:

1. In a device as described, a plurality of air compressors each having a cylinder having the characteristics of being long compared with its cross sectional area, a piston and piston rod for each cylinder, each piston rod having a driving means including a clutch with a continuously driven element for each clutch, means forming a source of initially compressed air, a Valve operatively connected between the compressed air source and each of the cylinders, an interconnecting means for the valves and means to control the operation of the valves and of the clutches whereby when compressed air from the source is supplied to a first cylinder to raise its piston and piston rod, the clutch for such cylinder is open and when such piston and piston rod is forced outwardly, such valve is closed and the clutch closed for a power stroke and a discharge outlet for compre'sse'dairfrom each of the cylinders.

2. In a device as described and claimed in claim 1, the interconnecting means for'the valves including meshing gears each connected to a valve, a lever attached to one of the gears and means operated in conjunction with each piston to shift such lever and thereby cause the opening of one valve and the closing of another.

3. Ina device as described and claimed in claim 1, the means to open and close the clutches including a quick acting type of connection for each clutch with an operative means actuated by each piston rod whereby when one cylinder is fully charged with air from the source, the clutch for such cylinder is closed to develop a power stroke, the clutch for another cylinder being opened when such cylinder completes its power stroke.

4. In a device as described, the combination of a plurality of air compressor cylinders each having the characteristic of being long compared with its cross-sectional area, each having a piston and a piston rod, a rack connected to each rod, a pinion meshing with each rack, a clutch to drive each rack, each clutch having a constantly driven element with a power means for constantly driving all of the clutch elements, means forming an initial source of compressed air, an air duct means from the source to each cylinder at the bottom thereof, each duct having a control valve, means to interlink the control valves, a clutch control means having an operative connection to each piston whereby when a piston is at the top of its stroke with its cylinder fully charged with air from the said source, the clutch for such cylinder is closed, a valve control also operated by each piston on its initial downward stroke to close the valve leading to such cylinder and open the valve controlling the flow of air from the source to another cylinder.

5. In a device as described and claimed in claim 4, each disc having a closed bottom head and a movable head, means securing the piston rod to the movable head and a resilient means reacting between the closed and the movable head whereby should the closed head strike the bottom of the long cylinder the closed head, piston rod and rack may move downwardly against a resilient pressure.

8. In a device as described, the combination of a plurality of air compressor cylinders each hav ing the characteristics of being long compared with its cross-sectional area, each having a piston and a piston rod, a thrust means connected to each piston rod for moving each piston inwardly on a power stroke, a power drive for each thrust means including a clutch for each piston rod and piston, each clutch having an element with means for constantly driving all of the elements, an initial air compressor, means for constantly driving such air compressor, air fiow'connections from the primary air compressor to each of the long cylinders at the base thereof and each connection having a valve, means interlinking the valves whereby, when one valve is opened, another valve is closed, a clutch control means for each of the compressor cylinders having means to close a clutch corresponding to a cylinder when such cylinder reaches the uppermost part of its stroke and a means to open the same clutch when the cylinder reaches the bottom of its stroke, means actuated by a cylinder on starting its downward power stroke to operate a. pair of valves simultaneously to thereby close the valve leading to the cylinderunde'r the power stroke and open the valve to another cylinder whereby the lowered piston in such other cylinder is elevated by compressed air from the primary compressor, the clutch of said second cylinder being open.

'7. A device as described and claimed in claim 6, the means to operate the clutch including a crosshead operatively connected to each piston rod, a shiftable rod having a clutch controlled means with an element engageable by the crosshead when such crosshead is in its uppermost and its lowermost positions.

8. A device as described and claimed in claim 6,

means to operate the valves including a rod with an operative connection to each piston, each piston rod having a crosshead connected thereto with a valve controlling rod attached thereto to move the crosshead, an operating lever arm connected to one of the valves and a pawl on each of said operating rods to engage the lever arm whereby on initial downward movement of an arm connected to a piston rod, operating on a power stroke the pawl on such rod operates the lever arm to thereby close one valve and open the other valve.

9. In a device as described, an air compressor cylinder having the characteristics of being long compared with its cross-sectional area, an air supply and airdischarge connection from the bottom of such cylinder, each having a check valve, means to charge air under an initial pressure into the cylinder, a piston in the cylinder having a piston rod to thereby raise such piston and piston rod, a power means including a clutch to force the piston rod and piston downwardly, means operatively connected to the piston rod to open the clutch adjacent the bottom of the stroke, the piston having a cylindrical wall with a closed bottom head and open at the top, movable head with the piston rod connected thereto and a reaction spring between the closed and movable heads whereby should the closed head contact the bottom of the cylinder, the movable head may continue downwardly against the compression of the spring.

10. A device as described and claimed in claim 9, a second similar cylinder having a similar piston rod and piston with its own power drive including a clutch, a valved air connection for compressed air to each of the cylinders, and means operated by the first cylinder on its downward and power stroke to reverse the valves whereby the pressure air is shut off from the first cylinder and open to the second cylinder to thereby elevate the piston and piston rod of the second cylinder.

11. In a device as described, a pair of air compressor cylinders each having a piston and a piston rod, a source or" air under initial compression, interconnected supply valves from the source to each of the cylinders operative only to supply air to the compressor cylinders when the pistons are in proximity to the end of their power stroke, such valve being operative to close the connection from the source of supply to the cylinders when the pistons are retracted adjacent the end of the cylinders for the initiation of the power stroke, the air admitted to each cylinder being operative to retract the piston and piston rod of such cylinder, a power drive means for the piston rod of each cylinder to operate one piston at a time in its power stroke to compress the air in one cylinder and means to connect each power drive means to its piston for actuating a piston on its power stroke while the piston in another cylinder is on its retraction movement under the initially compressed air.

12. In a device as described, a first and a second air compressor cylinder with pistons, an initial air compressor, a supply connection with reversing valves therein from the initial compressor to each of the cylinders, a power drive means for the pistons of each of the compressors and a timing mechanism operative when the first piston is at the top and the second piston at the bottom of its compression stroke to connect the power drive to operate the first piston, a valve reversing means operated on the downward movement of the first piston to admit air from the initial compressor to the second cylinder and thereby retract such second piston and to close the air connection to the first cylinder, the air admitted,

to the second cylinder being operative to retract the second piston at a slower speed than the power stroke of the first piston whereby the first piston at the end of the compressing action in the first cylinder remains substantially at rest until the second piston in the second cylinder reaches the end of its retraction stroke and the power drive connection and the reversing valve operation is being repeated in a cycle and an outlet for the compressed air from each of the compressor cylinders.

13. In a device as described, a first and a second closed chamber for compression of air, an initial air compressor, means to fill the first chamber with air from the initial air compressor and means operative at substantially the same time to compress the air in the second compressor, 'the rate of compression in the second compressor being faster than the filling of the first compressor with initially compressed air, means to develop a time pause on the complete compression in the second compressor chamber while the first compressor chamber is filled with air and thereby provide a time period for the dissemination of heat, means to discharge compressed air from the first and second chambers and means to reverse the cycle of operations.

14. In the method of compressing air in which the air is compressed in a first and a second con fining chamber comprising charging the first chamber with initially compressed air and at substantially the same time compressing initially compressed air in the second chamber causing the rate of compression in the second chamber to be at a greater rate than the filling of the first chamber with the initially compressed air, producing a time pause after the complete compression in the second chamber before the first chamber is completely filled and thereby providing a time period for dissemination of heat from the second chamber and continuing the with air to retract its piston and piston rod in a sequence as to the cylinders and means operative after any one cylinder is fully charged with air to exert a power stroke on the piston rod to compress the air in such cylinder and an air discharge means fromseach of the cylinders, the means to exert a power stroke on each of the piston rods including each rod having a rack, a pinion meshing with each rack, a clutch assembly operatively connected to each pinion, each clutch assembly having an element constantly driven and means to close each clutch in a sequence, the closing being efiected when a cylinder is charged with air and its piston retracted.

16. In a device as described, a plurality of air compressor cylinders, each having a piston and a piston rod, means to supply each of the cylinders with air to retract its piston and piston rod in a sequence as to the cylinders and means operative after any one cylinder is fully charged with air to exert a power stroke on the piston rod to compress the air in such cylinder and an air discharge means from each of the cylinders, the means to supply the cylinders with air including an initial source of compressed air, a system of valved piping from the initial source of compressed air to each of the cylinders and means to actuate the valves whereby when one valve is open tosupply compressed air to a first compressor cylinder, the valve to a second compressor cylinder is closed whereby in the first cylinder the piston and piston rod is elevated by the compressed air from the supply source and in the second cylinder the air may be compressed by the power stroke in such second cylinder.

S VE PY'ILEW I- 

